Improvement in helices for magnets



UNITED STATES LEVERETT BRADLEY,

PATENT OFFICE.

OF NEr YORK, N. Y.

IMPROVEMENT IN HELlClES FOR MAGNETS..

lpecitiention forming part of Letters Patent No. 49,074, lated August 1, 1865.

15') all whom 'it 'may concern:

Be it known that I, LEVERETT BRADLEY, ot'

` the' city, coi'iuty, and State of New York, have fore constructed, generally consist of a copper` wire covered with silk or other non-conductor of electricity, and wound uniformlyr andnin' reigular tiers on. a central core or bobbin,"'so that each turn of the wire will be in juxtaposition, as well as each layer of the coil forming the helix. rlhe objection to helices thus formed is that the covering'wound around the wire to insulate it (when small wire is used, and of which helices are generally made) almost doubles its size. Therefore the length of wire contained on a helix of a given size is diminished by the space occupied by the covering on the wire, Awith a proportionate decrease in the power ot' the helix, as the ,power ot' helices ot the saine size, as is well known, is in a great measure proportioned to the length ot' wire contained on the helix.

Another objection in constructing helices with covered wire is the expense of the covered wire over t-he uncovered, it costing nearly six timesas much, and the consequent increase in the cost ofthe helix.

The object of my invention is to overcome these objections, and to produce a cheap and more powerful helix, and at less cost than those heretofore made.

My invention for effecting this object consists in constructing a helix of uncovered wire wound in regular layers, connected with each other around a core or center, with sufficient space between theseveral turns of the wire to perfectly separate or insulate them from each other, and also with the dierent spires or tiers of wire ,forming the helix separated by the interposition ot' paper or other nou-conductor of electricity.

whole space .between the heads. Between the several turns or convolutions of the wire a space,

a, is left of sufficient width to insure the se'paration ofthe convolutions from each other. Be-

tween the several spires or tiers ot' the continuous coil of wire forming the helix is placed a stripof thin paper-11, or other nonconduetor,

so as to separate the different tiers of wire, leaving them only connected at the ends; l have found by actual experiment that in helices ofthe same size, made with the same number of'wire, nearly onethird more wire is contained in the helix when uncovered wire is used than wherrcowered wire is used, and that the power ot' the helix is proportionallyl increased, while the cost of the helix is greatly diminished. Y I do not conneniyself to the precise form, construction, 'orr material of thehelix as described, as these may be varied as circumstances may regui'i'f'aprovided, however, uucovered wire is' used, with a space between the several turns, and with the different layers or tiers of the coil separated by some non-conductor of electricity.

Having thus described my improvement in helices for electro-magnets, induction-coils, and other purposes, what I' claim as new, and desire to secure by Letters Patent, is-

A helix composed of two-or more connected spires or tiers of uncovered wire with su'icieut space between the several turns of the wire to perfectly separate them from each other, and with the dili'erent tiers of wireformiug the helix also separated (except at the ends) by the interpositiou of some non-conductor oi'electricity.

1n testimony whereofI have subscribed my name.

L. asentar.

In presence of- WM. D. BALDWIN, F. S. MYER, 

